2. Copyright © 2004 Patrick McDermott UC Berkeley Extension pmcdermott@msn.com

3. 11. Murphy’s Law Captain Edward A. Murphy, Jr. –U.S. Air Force, 1949 The Bread Always falls Butter side Down Files are Always lost just before Backup The bad news: –Many I.T. people know O’Niel’s Law: “Murphy was an optimist.” Anything that Can Go Wrong Will Go Wrong

4. Silver 12. No Silver Bullet Software is Hard! Brooks, Frederick P., Jr., “No Silver Bullet: Essence and Accident in Software Engineering” (1986) reprinted in Brooks, Frederick P., Jr., The Mythical Man-Month: Essays on Software Engineering, Anniversary Edition, Reading, Massachusetts: Addison-Wesley (0-201-83595-9), 1995 (1975)

5. 13. Pareto Principle The 80%-20% Rule Vilfredo Pareto ( 1848-1923) –Italian Economist Income, Employment Bugs, Problems Maybe Even 90/10! The Red bars are 20% of the Entities But account for 80% of the Items BUT: Joel Spolsky’s Modification: Each wants only 20% But a different 20%

6. 14. Parkinson’s Law “Work Expands to Fill the Time Allotted” C Northcote Parkinson, 1954 Sometimes you Need an Arbitrary Deadline –Due on Tuesday, even if I’m not here –The work at home problem

7. 15. Populations aren’t People Seemingly against own interest –The individual’s and organization’s interests do not always align Manager’s project vs. Good of Company –“Have a Lousy Day!” Veblen’s Principle –A Change that Benefits Somebody –…usually Hurts Somebody Else Communities are A super-organism Or a bunch of Individuals Or a Swarm Crichton, Michael, Prey, New York: HarperCollins (0-06-621412-2), 2002.

8. 16. Shapiro’s Observation Technology changes—Economic Laws do not. Silicon Circuits evolve much more quickly than Human Genes. Social systems change incrementally, Technology exponentially. Shenk, David, Data Smog: Surviving the Information Glut, New York: HarperEdge (0-06-251551-9), 1997, p. 42. Shapiro, Carl & Hal Varian, Information Rules: a Strategic Guide to the Network Economy, Boston: Harvard Business Review Press (0-87584-863-X), 1999, p. 2.

9. 17. Slingerland’s Rule of Fools No System is Foolproof, … because there’s Always a Bigger Fool –The General’s Landing     

10. 18. TINSTAAFL There is No Such Thing as a Free Lunch There is always a Trade Off Processing vs. Memory –Compression versus Storage –Save versus re-compute

11. 19. Unintended Consequences All Changes Have Effects that weren’t Intended and not Expected Culture + New Technology  New Culture 1 st Law of Ecology –Everything is Connected to Everything Else –You can Never Do Just One Thing. Barry Commoner, The Closing Circle

12. Unintended Consequences Emergence’s Evil Twin –Freeway Fliers & Contract Programmers –Email & Spam: Productivity Paradox –Labor Saving Devices and Long Hours –Environmental Damages –Peltzman Effect & Seatbelts The Only Defense: Expect the Unexpected Tenner, Edward, Why Things Bite Back: Technology and the Revenge of Unintended Consequences, New York: Vintage Books (0-679-74756-7), 1996.

13. 20. Many Ways to Mountaintop T>1W2DI: There’s more than 1 Way to Do It We’ve found the One Best Way –About 100 of them If you fail, try something different If life is a climb to the summit, you and I might take a different route, but we can both reach the top, and enjoy the view together. PMcD Hokusai Katsushika 1760-1849